Airflow generating apparatuses are a key part for devices whose operation relies on airflow, such as hair dryers, hand dryers or vacuum cleaners. The efficiency of the airflow generating apparatus also directly affects the efficiency of these devices. Therefore, in order to enhance the efficiency of these devices, improvement of the efficiency of the airflow generating apparatus has become an important subject to study.
A typical airflow generating apparatus includes a motor, an impeller and a diffuser. The diffuser surrounds the impeller, the impeller is driven by the motor to rotate, and the air entering the impeller passes through the diffuser and is finally discharged from openings of a motor housing.
The construction of the diffuser is vitally important because it affects the efficiency of the airflow generating apparatus. A high efficient diffuser can increase airflow, or reduce the power consumed to achieve the same airflow. Therefore, it is highly desirable for providing a high efficient diffuser and hence enhancing the efficiency of the airflow generating apparatus.